In the industrial field such as automobile and home electric appliance, a seal material for sealing various members is generally used for the waterproofing purpose. Such a seal material is composed, for example, of an elastomer composition containing a thermosetting elastomer-made base material, a crosslinking agent and the like and having a crosslinked structure formed in the inside, or an elastomer composition described in Patent Document 1.
Also, in a wire harness routed in an automobile, for example, a waterproof connector 101 shown in FIG. 4 is used for preventing a liquid such as water from intruding into the connector to corrode a terminal fitting.
The waterproof connector 101 comprises a terminal fitting 102 formed by pressing an electrically conductive sheet metal or the like and a connector housing 103 for housing the terminal fitting 102. The terminal fitting 102 comprises an electric wire connection part fixed to an end 106a of an electric wire 106 to establish connection of the core wire of the electric wire 106, and an electric contact part connected to the terminal fitting of the other-party connector. The connector housing 103 is made of an insulating synthetic resin or the like and formed in a box shape. The connector housing 103 comprises a terminal housing chamber 103a for housing the terminal fitting 102 in the inside. In the terminal housing chamber 103a, a potting material 104 as a seal material is injected.
The potting material 104 is composed of, for example, a liquid silicone rubber or an epoxy resin. The potting material 104 injected into the terminal housing chamber 103a is cured by forming a crosslinked structure in the inside after a curing time under the predetermined temperature condition. Thanks to such curing of the potting material 104, a liquid such as water is prevented from intruding into the terminal housing chamber 103a, that is, the waterproof connector 101.
As for the waterproof connector not using the potting material, the following waterproof connector is known. This waterproof connector comprises a terminal fitting, a connector housing, as described above, and a tubular holder fixed to the outside surface of an electric wire and at the same time, fixed to the connector housing. In the connector housing, a concave part for housing the holder is provided.
On the inside of the holder, a tubular packing put into close adherence to both the inner surface of the holder and the outside surface of the electric wire is fixed. Also, on the outside of the holder, a tubular packing put into close adherence to both the outer surface of the holder and the inner surface of the concave part of the connector housing is fixed. Furthermore, in the portion between the electric wire connection part and the electric contact part of the terminal fitting, an O-ring put into close adherence to both the outer surface of the terminal fitting and the inner surface of the connector housing is fixed.
Thanks to the configuration above, the portion between the holder and the electric wire, the portion between the holder and the connector housing, that is, between the electric wire and the connector housing, or the portion between the terminal fitting and the connector housing is kept watertight, and a liquid such as water is prevented from intruding into the waterproof connector.